Criteria 3 of ADL2A has been implemented to eliminate air conditioning or to reduce the potential load on the air conditioning systems within new buildings.

This is achieved by limiting the solar gains entering the building through the windows and roof lights. Whilst in dwellings this is not a significant problem it can be a significant problem in commercial buildings.

Architects strive to get as much natural light into modern buildings as possible. Glass which lets in light to reduce lighting loads also lets in lot of solar heat when it is sunny, but they also let out a lot of heat when there is no sun. therefore, the amount and type of glass is key to the buildings performance.

Also, the rules on the amount of glazing that is allowed in a non domestic building are well defined in ADL2A criteria 3. That is why it is important to run the SBEM as early in the building design process as possible.

This is a typical ‘see saw’ conundrum that HIBEC Ltd can help you solve.

However, this is not always possible, as many other import building parameters may not yet be decided and that information is required for the SBEM.

At HIBEC Ltd we recognise this chicken and egg situation and have a solution:

HIBEC Ltd have developed a useful little calculation tool that will estimate the solar overheat of a simple “side lit” room.

Using only the room orientation and dimensions, you can establish the criterion 3 compliant glazing area based on your choice of glass g value and shading, so you will know you are on the right track from the start.

You are welcome to a free copy of this excel spreadsheet tool, please email us and we will send it to you.